Apple Final Cut Express HD - Manual (Page 1028)

1028 Part XIII Appendixes
High Definition Video
In the late 1990s, high definition video formats were standardized in the United States
by the ATSC (Advanced Television Standards Committee). These high definition video
formats are the next generation of broadcast and recording video formats. Unlike
standard definition formats, which are restricted to fixed frame rates and number of
lines per frame, HD video provides several options per format. While the increased
flexibility is convenient, it also makes format interchange more complicated. Simply
saying “high definition video” is not enough; you need to define the frame size, frame
rate, and scanning method of your HD format.
There are an increasing number of HD tape formats available. Most HD formats only
support a subset of the options shown in the table above, and most camcorders and
video decks do not support every combination.
Type of Video Signal
Video signals are separated into several channels for recording and transmission. There
are different methods of color channel separation, depending on the video format and
historical origins. For example, broadcast video devices were originally designed for
black-and-white video, and color was added later. This is still evident in today’s video
formats that break image information into separate black-and-white and color
information. On the other hand, video and image processing on computers is more
flexible and developed later, so a three-color RGB model was adopted instead of a
luma-chroma model.
Standard Frame size Frame rates Scanning method
720p 1280 x 720 23.98, 29.97, 59.94
24, 30, 60
25 Progressive
1080p 1920 x 1080 23.98, 29.97
24, 30
25 Progressive
1080i 1920 x 1080 25 (50i), 29.97 (59.94i),
30 (60i) Interlaced